Khuram Zaman

Bio: Khuram Zaman is an academic researcher from University of Wisconsin-Madison. The author has contributed to research in topics: Population & Threatened species. The author has an hindex of 3, co-authored 3 publications receiving 21 citations. Previous affiliations of Khuram Zaman include University of the Pacific (United States).

Population ecology of a California endemic: Speyeria adiaste clemencei

Abstract: Effective management and recovery of threatened insect populations requires detailed ecological information. Here we combine count and mark recapture (MR) data to shed light on an understudied declining endemic butterfly species in California’s Southern Coast Ranges, Speyeria adiaste. Little is known about the number, size, and dynamics of S. adiaste populations, leaving few data on which to base conservation decisions. Our goal in this study was therefore to provide increased understanding of the population ecology of this species by studying a long-standing S. adiaste clemencei population. Our 2-year MR estimates were highly correlated with Pollard walk counts, and we observed declining population sizes from 2011 to 2014. Adult movements were well-described by a negative exponential function, indicating low probability of dispersal >5 km (probability < 1.8 × 10−7 for both sexes). Males had shorter lifespans than females. Coupled with lack of diapause in this species, the short life span and limited dispersal observed here indicate that S. adiaste clemencei does not have a strong capacity for re-colonization. Population declines in S. adiaste may lead to local extinctions, and together with low dispersal, may diminish connectivity among the apparently small and isolated remaining populations. Further research into the role of adult and larval resources for determining adult abundance, coupled with continued long-term monitoring is necessary in order to understand population dynamics in this declining endemic species.

Testing the role of ecological selection on colour pattern variation in the butterfly Parnassius clodius.

Abstract: Colour pattern has served as an important phenotype in understanding the process of natural selection, particularly in brightly coloured and variable species like butterflies. However, different selective forces operate on aspects of colour pattern, for example by favouring warning colours in eyespots or alternatively favoring investment in thermoregulatory properties of melanin. Additionally, genetic drift influences colour phenotypes, especially in populations undergoing population size change. Here, we investigated the relative roles of genetic drift and ecological selection in generating the phenotypic diversity of the butterfly Parnassius clodius. Genome-wide patterns of single nucleotide polymorphism data show that P. clodius forms three population clusters, which experienced a period of population expansion following the last glacial maximum and have since remained relatively stable in size. After correcting for relatedness, morphological variation is best explained by climatic predictor variables, suggesting ecological selection generates trait variability. Solar radiation and precipitation are both negatively correlated with increasing total melanin in both sexes, supporting a thermoregulatory function of melanin. Similarly, wing size traits are significantly larger in warmer habitats for both sexes, supporting a Converse Bergmann Rule pattern. Bright red coloration is negatively correlated with temperature seasonality and solar radiation in males, and weakly associated with insectivorous avian predators in univariate models, providing mixed evidence that selection is linked to warning coloration and predator avoidance. Together, these results suggest that elements of butterfly wing phenotypes respond independently to different sources of selection and that thermoregulation is an important driver of phenotypic differentiation in Parnassian butterflies.

Improving our science: the evolution of butterfly sampling and surveying methods over time

Abstract: Butterflies are consistently the focus of conservation research because they contribute to ecosystem services, act as biological indicators, and are in decline worldwide. Land managers and researchers use many methods to measure butterfly populations, but this creates issues for standardization and production of comparative, rigorous data. To promote methods more appropriate for research-based conservation, we conducted a literature review focusing on the implementation and advancement of butterfly monitoring methods over time. We identified four main methods that are most frequently used in butterfly research and monitoring: (1) trapping and netting, (2) mark-recapture, (3) transects (Pollard walks), and (4) distance sampling. Although a progression of method development has occurred over time, all methods are still currently used in butterfly research, with trapping, netting, and mark-recapture used in 85% of studies. Over the last century, the amount of butterfly research has steadily increased, so it is vital to select methods that produce accurate, and comparable data. However, we found that method selection was not solely based on the type of data needed for accurate interpretation and extrapolation of results. Instead, land context, species abundance, and historically-used methods are driving method selection. As butterflies remain a high conservation priority, researchers must provide rigorous data that are necessary for creating effective conservation plans and policies by using a framework for method selection.

Interrelationships and diversification of Argynnis Fabricius and Speyeria Scudder butterflies

Abstract: Diverse radiations of insects are often associated with adaptations to host plants, and well-resolved phylogenetic relationships are required to fully understand them. Palearctic Argynnis and related subgenera, together with North American Speyeria butterflies make up a radiation whose species hypotheses are confounded by shared wing colour patterns between sympatric populations of closely related recognized species. Previous studies of this group indicate that Speyeria is a lineage within Argynnis, but sampling in these studies has either involved too few Speyeria species or incomplete sampling of Argynnis species. Thus, no comprehensive phylogenetic analysis exists for all members that answers the question of monophyly of Speyeria, or other subgeneric taxa, and their relationship to Argynnis species. We completed a phylogenetic analysis of all North American Speyeria species and all but one species within Argynnis, using one mitochondrial (cytochrome c oxidase I, COI) and four nuclear genes [elongation factor 1 alpha (EF1α), wingless (WG), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and ribosomal protein S5 (RPS5)]. The results indicate three major lineages within Argynnis s.l.: two Palearctic and one containing both Palearctic and Nearctic species. In summary, the phylogenetic analyses suggest the need for reorganization into three natural groups: Argynnis, Fabriciana and Speyeria. Within each of these genera the phylogenetic hypothesis indicates an evolutionary history marked by rapid diversification and potential extinction, followed by ongoing lineage sorting. The position of North American Speyeria is nested within the Palearctic lineages, which indicates that the radiation began in Asia and was fuelled by existing Viola diversity in North America. Dating analyses of Viola and Speyeria corroborate this hypothesis. The current North American Speyeria species are mixed on the tree, indicating a recent and ongoing radiation. These results provide needed clarity on the evolution of this group, which contains species of conservation concern.

Single nucleotide polymorphism‐based species phylogeny of greater fritillary butterflies (Lepidoptera: Nymphalidae: Speyeria) demonstrates widespread mitonuclear discordance

Abstract: The systematics of Speyeria butterflies has historically been complicated by intraspecific variability that has challenged efforts to delimit species and reconstruct phylogenies. Our study presents a phylogenetic comparison of genomic single nucleotide polymorphisms (SNPs) and mitochondrial COI gene sequences, with comprehensive taxon sampling that includes 15 species and 46 subspecies. Increased sampling of genetic markers and taxa improved the match between genetic clusters, obtained with both phylogenetic and cluster‐based analyses, and species previously detected using morphology, as well as showing two species delimitations that may need revision. We also recovered extensive mitonuclear discordance between genomic SNPs and the COI gene, confirming that mitochondrial DNA does not reliably identify several species at broad geographic scales. Resolution of the relationships of Speyeria species demonstrates the importance of sampling variation across the whole genome, and provides an essential foundation for understanding the evolution of this charismatic clade of North American butterflies.

Population ecology of a California endemic: Speyeria adiaste clemencei

Abstract: Effective management and recovery of threatened insect populations requires detailed ecological information. Here we combine count and mark recapture (MR) data to shed light on an understudied declining endemic butterfly species in California’s Southern Coast Ranges, Speyeria adiaste. Little is known about the number, size, and dynamics of S. adiaste populations, leaving few data on which to base conservation decisions. Our goal in this study was therefore to provide increased understanding of the population ecology of this species by studying a long-standing S. adiaste clemencei population. Our 2-year MR estimates were highly correlated with Pollard walk counts, and we observed declining population sizes from 2011 to 2014. Adult movements were well-described by a negative exponential function, indicating low probability of dispersal >5 km (probability < 1.8 × 10−7 for both sexes). Males had shorter lifespans than females. Coupled with lack of diapause in this species, the short life span and limited dispersal observed here indicate that S. adiaste clemencei does not have a strong capacity for re-colonization. Population declines in S. adiaste may lead to local extinctions, and together with low dispersal, may diminish connectivity among the apparently small and isolated remaining populations. Further research into the role of adult and larval resources for determining adult abundance, coupled with continued long-term monitoring is necessary in order to understand population dynamics in this declining endemic species.